428 HOMES WITHOUT HANDS. 



hooks wherewith it clings to its habitation. It is but a little 

 creature in point of length, but in point of width it nearly fills, 

 the diameter of the tube. The extremity of the body, however, 

 is very small and slender, and is doubled back upon itself, with 

 its tip pointing to the mouth of the tube. 



The structure of the tube is extremely variable. Some indi- 

 viduals seem to give all their endeavors toward making their 

 dwelling as long and strong as possible, while others are content 

 with a tube which is barely long enough to shelter the whole 

 body. They work with great rapidity, and, when confined in an 

 aquarium, will build their sandy homes nearly as well as if they 

 were at liberty in the sea. Many interesting experiments have 

 been made upon their modes of working, and by a judicious sup- 

 ply of different substances they may be forced to build tubes of 

 various colors and forms. 



Very little care is required in keeping the Sabella in the aqua- 

 rium. The beautiful little worm requires no feeding, and the. 

 only precaution that is needed is to see that the water is pure. 

 All dead animals should be carefully removed from the aquari- 

 um, as they are sure to putrefy very quickly, and the noxious 

 gases evolved in that process will soon destroy all the other in- 

 habitants. 



Generally, when the Sabella feels ill, it is obliging enough to 

 come out of its cell and die, in full sight ; but now and then one 

 of them will retreat to the bottom of its cell and die there, in 

 which case it is as noisome and as difficult to discover as a dead 

 rat behind the wainscot. Still, although the number of apertures 

 in a single group of Sabella tubes renders it difficult for the pos- 

 sessor to identify the particular tube in which the defunct worm 

 may be lying, its presence can generally be detected by a kind of 

 whitish growth that appears at the mouth of the tube, and that 

 tells its tale to an experienced eye. The best plan of getting out 

 the inmate is by a slender wire hooked at the end. This can be 

 pushed down to the very bottom of the cell, when a twist of the 

 wire will mostly secure the dead worm, and the nuisance may 

 thus be removed. 



Another species belonging to this genus, the Straight Sabel- 

 la {Sabella unispira), is remarkable for the form of its tube, which 

 is nearly cylindrical, and scarcely possesses any curve at all. 



There is another group of tube-making marine annelids which 



